Re: [PATCH V2 3/9] ARM: stm32: prepare stm32 family to welcome armv7 architecture

[Ludovic BARRE]

On 12/19/2017 04:26 PM, Arnd Bergmann wrote:
> On Tue, Dec 19, 2017 at 3:43 PM, Ludovic BARRE <ludovic.barre@xxxxxx> wrote:
> > On 12/18/2017 09:24 PM, Arnd Bergmann wrote:
> > > On Mon, Dec 18, 2017 at 4:17 PM, Ludovic Barre <ludovic.Barre@xxxxxx>
> > > wrote:
> > > > From: Ludovic Barre <ludovic.barre@xxxxxx>
> > > >
> > > > This patch prepares the STM32 machine for the integration of Cortex-A
> > > > based microprocessor (MPU), on top of the existing Cortex-M
> > > > microcontroller family (MCU). Since both MCUs and MPUs are sharing
> > > > common hardware blocks we can keep using ARCH_STM32 flag for most of
> > > > them. If a hardware block is specific to one family we can use either
> > > > ARM_SINGLE_ARMV7M or ARCH_MULTI_V7 flag.
> > > >
> > > > Signed-off-by: Ludovic Barre <ludovic.barre@xxxxxx>
> > >
> > >
> > > Looks good overall. Two more small comments:
> > >
> > >
> > > > +if ARCH_STM32
> > > > +
> > > >    config MACH_STM32F429
> > > > -       bool "STMicrolectronics STM32F429"
> > > > -       depends on ARCH_STM32
> > > > +       bool "STMicroelectronics STM32F429"
> > > > +       depends on ARM_SINGLE_ARMV7M
> > > >           default y
> > >
> > >
> > > Instead of the explicit dependency for each board, I'd leave the
> > > surrounding
> > > 'if ARM_SINGLE_ARMV7M'. I think you had in v1.
> >
> >
> > As you suggest, I follow mach-at91 example.
> > The point is on "depends on ARM_SINGLE_ARMV7M" ?
> > You prefer this way:
> > config MACH_STM32F429
> >          bool "STMicroelectronics STM32F429" if ARM_SINGLE_ARMV7M
> >          default y
>
> No, that would be wrong, that way you would always enable
> MACH_STM32F429 when ARM_SINGLE_ARMV7M is turned
> off, which is exactly the wrong way round. What I meant is
>
> if ARCH_STM32
>
> if ARM_SINGLE_ARMV7M
>
> config MACH_STM32F429
>           bool "STMicrolectronics STM32F429"
>
> config MACH_STM32...
>            ...
>
> endif # ARMv7-M
>
> if ARCH_MULTI_V7
>
> config MACH_STM32...
>            ...
>
> endif # ARMv7-A
>
> endif # STM32
>
>         Arnd
Ok, it's clear :-)